<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>下拉框回显</title>
    <script src="/static/jQuery-1.11/jquery-1.11.3.min.js"></script>
    <SCRIPT>
        function echo() {
            $('#s1').val("3");
        }
    </SCRIPT>
</head>
<body>
<select id="s1">
    <option value="1">选项1</option>
    <option value="2">选项2</option>
    <option value="3">选项3</option>
    <option value="4">选项4</option>
    <option value="5">选项5</option>
</select>
<br/>
<input type="button" value="回显第3个选项" onclick="echo();"/><br/>
</body>
</html>
